Long-term evolution (“LTE”) is a wireless communication standard used for high-speed data for mobile devices and data terminals. LTE-Advanced is a major enhancement to the LTE standard. Within the LTE-Advanced standard, carrier aggregation is used to increase the bandwidth, and thereby increase the bitrates. Carrier aggregation was introduced in the 3rd Generation Partnership Project (“3GPP”) Release 10 (LTE-Advanced standard) and has been carried through to later Releases to provide wider than 20 MHz transmission bandwidth to a single device (e.g., user equipment or “UE”) while maintaining the backward compatibility with legacy UEs. Specifically, carrier aggregation may be defined as the aggregation of two or more component carriers to support wider transmission bandwidths.
Carrier aggregation configuration may be defined as a combination of carrier aggregation operating bands, each supporting a carrier aggregation bandwidth class by a UE. The bandwidth class may be defined by the aggregated transmission bandwidth configuration and maximum number of component carriers supported by a UE. For intra-band contiguous carrier aggregation, a carrier configuration may be a single operating band supporting a carrier aggregation bandwidth class. For each carrier aggregation configuration, requirements may be specified for all bandwidth combinations contained within a bandwidth combination set, as indicated by the radio access capabilities of the UE. Accordingly, a UE may indicate support of several bandwidth combination sets for each band combination. FIG. 1 shows an exemplary table 100 including the requirements for inter-band aggregation as defined for the carrier aggregation configurations and bandwidth combination sets.
Under the current LTE standards, each aggregated carrier is referred to as a component carrier, and each component carrier can have a bandwidth of 1.4, 3, 5, 10, 15 or 20 MHz and a maximum of five component carriers can be aggregated. As illustrated in FIG. 2, two exemplary component carriers may each have a bandwidth of 10 MHz to combine for a total bandwidth of 20 MHz. With carrier aggregation features enabled, the LTE-Advanced standard device supporting 20 MHz carrier aggregation may achieve downlink (“DL”) throughput of 100 Mbps.
It is possible for a UE utilizing carrier aggregation configuration to support an aggregate maximum bandwidth greater than the capabilities of the device. In other words, a UE limited to a certain bandwidth threshold may have component carriers exceeding that limitation through carrier aggregation. Accordingly, there may be scenarios in which the UE is allocated resources to a carrier components not necessarily having the highest available bandwidth within the UE's capabilities.